Hi Jason, > > In function ‘bitmap_copy’, > > inlined from ‘ap_matrix_copy’ at drivers/s390/crypto/vfio_ap_ops.c:1674:2, > > inlined from ‘ap_config_store’ at drivers/s390/crypto/vfio_ap_ops.c:1696:2: > > ./include/linux/bitmap.h:253:17: warning: ‘memcpy’ reading 32 bytes from a region of size 0 [-Wstringop-overread] > > 253 | memcpy(dst, src, len); > > | ^~~~~~~~~~~~~~~~~~~~~ > > In function ‘ap_config_store’: > > cc1: note: source object is likely at address zero > > I believe that this is a bogus compiler warning. I cannot reproduce it, > fwiw. > > gcc: gcc (GCC) 13.2.1 20231205 (Red Hat 13.2.1-6) > binutls binutils-2.40-14.fc39 ... > A quick web search seems to indicate gcc throws quite a few > Wstringop-overread warnings for valid code. I suspect this is > another example of that. This might be the case, however the code has to compile without warnings also with plain gcc 13.2.0 (built from source).
